There is a conventional high electron mobility transistor (HEMT) with a semiconductor laminate structure that includes a carrier running layer and a carrier supply layer. In recent years, a GaN-HEMT has been actively developed. By using heterojunction of AIGaN/GaN as a GaN-based compound semiconductor, the HEMT structure of the GaN-HEMT is formed where GaN as an electron running layer and AIGaN as an electron supply layer are layered.
The GaN is a material having a high breakdown field strength of which the bandgap is approximately 3.4 eV which is larger than the bandgap (approximately 1.1 eV) of Si and the bandgap (approximately 1.4 eV) of GaAs. The GaN is a material that has a high saturated electron velocity. Therefore, the GaN is expected to be used to achieve a semiconductor device for a power source that may operate with a high voltage and may obtain a high output. The GaN-HEMT is expected to work as a switching element with a high effect used for a power source device provided in an electron device.
The semiconductor chip with the above-described GaN-HEMT is mounted on a support plate of a circuit substrate, a stage of the lead frame, or the like. There is a technique for mounting the semiconductor chip on the support plate by bonding the back surface of the semiconductor chip with the semiconductor chip mounting area of the support plate by using a die bounding agent, such as a solder and an adhesive agent. For example, Japanese Laid-open Patent Publication No. 2006-156437, Japanese Laid-open Patent Publication No. 6-132442, and Japanese Laid-open Patent Publication No. 58-207645 are disclosed as the related art.